Fused Cast AZS Block For Glass Industry

The mostly applied type of refractory in the glass industry, in direct cont
act with the glass melt, is fused cast AZS block.

Zirconia is a very insoluble oxide in most glass melts and therefore has gr
eat corrosion resistance. However, in addition to being very expensive, zir
conia has a tendency to crack during manufacture and use, and is very diffi
cult to make in large shapes. Zirconia is therefore combined with oxides, u
sually alumina and silica, to descrease the solubility of the composite ref
ractory.
The fused cast AZS block is produced by melting the raw materials in an ele
ctric arc furnace at about 2200-2400 ?. The melt is treated with ox
ygen to oxidize zirconium oxy-carbo-nitride or other reduced constituents,
produced by the reaction with the graphite electrodes during melting. The m
olten material is then cast into molds to, or very near to, the final shape
of the block desired. The mold with the fused cast ceramic is cooled down
very slowly in order to anneal (free of thermal stresses) the fused cast pr
oduct.
The fused cast AZS block is available in a number of grades, principally di
stinguished by zircon content: 33#, 36# and 41#. Among the three, 33# and 4
1# are most widely used. For the most severe applications, the 41# is recom
meded. For less severe applications, 33# is used.
The AZS fused cast 33# blockcontains 33% ZrO2. It is unlikely to cause defe
ctions of stones, blisters and cords. Therefore, it is most suitable for su
perstructures of melters, side walls of refiners, paving blocks, and forehe
arth channel blocks.
The AZS fused cast 36# block contains 36% ZrO2. It is corrosion resistant a
nd shows minimal contamination against molten glass. It is most suitable fo
r glass contact parts of melters, and has shown considerable results in sid
e walls and paving blocks.
The AZS fused cast 41# block contains 41% ZrO2. It is highly corrosion resi
stant against molten glass, and by strengthening matrix glass, it shows min
imal contamination to molten glass. It is most suitable for glass melting f
urnaces; on throats of parts that demand high corrosion resistance, dog hou
se corner blocks, electrode blocks, bubbler blocks and electric furnaces.
The AZS fused cast block from Sunrise Refractory has passed the ISO interna
tional certified. High purity raw material, scientific formula, advanced te
chnology and professional guide all contribute to our qualified azs blocks
production.

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